反应详情

温度

0 °C

H2O2 (70%, 0.33 mL, ca. 6.7 mmol) was added dropwise to a stirred solution of TFAA (0.94 mL, 6.7 mmol) in DCM (10 mL) at 0° C. The solution was stirred at 0° C. for 5 min, warmed to 20° C. for 10 min, then cooled to 0° C. and added to a stirred solution of 1-oxide 6 (182 mg, 0.7 mmol) and TFA (0.10 mL, 1.3 mmol) in CHCl3 (15 mL) at 0° C. The solution was stirred at 5° C. for 4 h, diluted with dilute aqueous NH3 solution (10 mL) and extracted with CHCl3 (4×50 mL). The combined organic fraction was dried and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (0-10%) of MeOH/DCM, to give 1,4-dioxide 7 (60 mg, 31%) as a red solid: mp (MeOH/EtOAc) 153-156° C.; 1H NMR δ 8.12 (d, J=8.7 Hz, 1H, H-5), 7.70 (d, J=8.7 Hz, 1H, H-6), 7.37 (br s, 1H, NH), 3.71 (br t, J=7.4 Hz, 2H, H-9), 3.60-3.64 (m, 2H, CH2N), 3.03 (br t, J=7.8 Hz, 2H, H-7), 2.61 (t, J=6.0 Hz, 2H, CH2N), 2.30 [s, 6H, N(CH3)2], 2.17-2.26 (m, 2H, H-8); 13C NMR δ 149.1, 144.7, 138.6, 138.4, 132.7, 129.1, 115.8, 57.6, 45.2 (2), 38.8, 35.1, 32.9, 24.6; MS m/z 289 (M+, 0.5%), 273 (2), 256 (3), 58 (100); HRMS calcd for C14H19N5O2 (M+) m/z 289.1539, found 289.1536.

1. temperaturewarmed to 20° C. for 10 min
2. temperaturecooled to 0° C.
3. stirringThe solution was stirred at 5° C. for 4 h
4. extractionextracted with CHCl3 (4×50 mL)
5. customThe combined organic fraction was dried
6. customthe solvent evaporated
7. customThe residue was purified by chromatography
8. washeluting with a gradient (0-10%) of MeOH/DCM